1. Field of the Invention
The present disclosure relates to a contact apparatus for a circuit breaker, and more particularly, to a contact apparatus for a circuit breaker for alleviating a shock when contacting a contact.
2. Description of the Related Art
As is generally known, a circuit breaker is a kind of an electrical protector for protecting load devices and power lines when occurring a fault current such as ground fault or short circuit.
The circuit breaker may be classified into an oil circuit breaker using oil as an extinguishing medium, a gas circuit breaker using sulfur hexafluoride (SF6) gas or the like, an air circuit breaker using air as an extinguishing medium, and a vacuum circuit breaker using vacuum insulation strength according to the type of extinguishing medium.
The circuit breaker may include a stationary electrode portion, a movable electrode portion for opening or closing a (main) circuit while being brought into contact with and separated from the stationary electrode portion, and a mechanism unit for providing a driving force to the movable electrode portion.
FIG. 1 is a view illustrating an example of a circuit breaker in the related art, and FIG. 2 is a partial enlarged view of FIG. 1. As illustrated in FIG. 1, a circuit breaker may include an enclosure 10 forming an accommodating space therein, a vacuum circuit breaker 20 disposed at an inner portion of the enclosure 10, and a mechanism unit 50 disposed at a side of the enclosure 10 to provide a driving force to the vacuum circuit breaker 20.
The vacuum circuit breaker 20, as illustrated in FIG. 2, may include a vacuum container 21 for forming vacuum therein, a stationary electrode portion 30 fixed and disposed at a side of the vacuum container 21, and a movable electrode portion 40 disposed to be brought into contact with and separated from the stationary electrode portion 30.
The stationary electrode portion 30 may include a stationary contact 31, and a stationary conductor portion 33 formed to be electrically conducted to the stationary contact 31. A bushing 70 electrically connected to either one of a busbar or load may be provided at a side of the stationary electrode portion 30.
The movable electrode portion 40 may include a movable contact 41 disposed to be brought into contact with and separated from the stationary contact 31, and a movable conductor portion 43 one side of which is connected to the movable contact 41 in an electrically conductive manner and the other side of which is extended out of the vacuum container 21 in a relatively movable manner. A bushing 70 connected to either one of a busbar or load may be provided at a side of the movable electrode portion 40.
The mechanism unit 50 may include a plurality of links, springs, motors, and the like to provide a necessary driving force such that the movable electrode portion 40 is promptly brought into contact with and separated from the stationary electrode portion 30.
A power transfer mechanism 60 for transferring a driving force of the mechanism unit 50 to the movable electrode portion 40 may be provided between the movable electrode portion 40 and the mechanism unit 50.
However, in such a circuit breaker in the related art, since the movable conductor portion 43 and the movable contact 41 constituting the movable electrode portion 40 may be configured in an integrated manner, a mass of the movable electrode portion 40 may be relatively larger during a closing operation, thereby causing an excessive shock when contacting a contact. Due to this, the damage of a component may occur.